AI Improvements: Performance Tuning in All the Mods 10

AI Improvements: Performance Tuning is a small, server-minded mod that makes vanilla mob AI cheaper to run. It also lets you switch off certain AI behaviors. It targets problems like too many animals and performance hits from swarms of zombies.^[1]

This pack ships version 0.5.3 of the mod. It has been in the pack since 2.25 or earlier.^[2]

How it helps

Most of the gain comes from caching heavily calculated values. That cuts CPU time at the cost of an ignorable amount of RAM. The main feature replaces the game's EntityLookHelper with a more efficient version that stores data to find the angle to a location faster. The author's VisualVM testing showed a 50% to 80% decrease in CPU usage by the AI code. On a server with 25 people online constantly, that meant a gain from 5 to 7 tps.^[1]

The mod also has two optional switches. One removes the AI segment that makes mobs turn their heads toward a nearby entity. The other removes the 'look idle' AI. The author says both can free up CPU, with the visual cost of odd or missing head rotation. The project page describes both as off by default.^[1]

Who it is for

It is built for large, heavily modded servers where mobs and other entities eat into CPU time. You can install it on the server only, since it works without a client-side copy. Client-only installs are possible, but it may not do much for your fps.^[1]

Unverified The sources do not show how the pack configures this mod, so the defaults described above come from the mod's project page and are not confirmed as this pack's values. They also do not show any quest or ATM Star path involvement, so there is no progression step tied to it.

This one is different from most mods in the pack: AI Improvements: Performance Tuning isn't something you craft or build with. It works quietly in the background, making vanilla mob AI cheaper to run and letting you switch off certain AI behaviors. So your first steps are about testing and settings, not items.^[1]

Unverified The sources here show no recipes, quests or guidebook entries for this mod, so there is no first item to craft. The option defaults below are the mod's own defaults from its project page, and the sources here do not show whether the pack changes any of them.

What to do first

1. Measure before you decide. The mod's author says it isn't expected to improve performance in every case, so test your results to see whether you actually need it.^[1]
2. Know where it runs. It can be installed on the server only, which is the setup it grew out of. It also works on the client only, though it may not do much for your FPS there.^[1]
3. Set your expectations. Newer Minecraft versions already include AI fixes, such as the rotation fix, so the gain is much smaller than in older versions.^[1]
4. Find the config. The project page says the mod's config file is at .minecraft/config/bbm/AI_Improvements.cfg.^[1]

The main options

The project page describes these config options, with the defaults the mod ships with. Most of the savings come from caching heavily calculated values, which trades a negligible amount of RAM for less CPU time.^[1]

• Disable AI Watch Closest Entity: off by default. When on, it removes the AI segment that makes mobs turn their heads toward nearby entities. It frees up a lot of CPU, but you may notice some odd visuals.^[1]
• Disable AI look random: off by default. When on, entities stop using the idle look AI. This can help servers with large populations, and the only visible effect is that heads sometimes don't rotate, which mostly goes unnoticed.^[1]
• Replace EntityLookHelper with a more efficient version: on by default. If you turn it off, you won't see much AI improvement, though the other disable options should still work fine.^[1]

This one is different from most mods on the wiki. The project page describes no machines, multiblocks, power, fluids or item automation. It is a performance mod that changes how vanilla mob AI runs, so the core mechanics are about what it changes behind the scenes.^[1]

Most of the performance gain comes from caching values that are expensive to calculate. That cuts CPU time at the cost of an ignorable amount of RAM. How much you gain depends on the feature and the Minecraft version.^[1]

The features

• Replaced EntityLookHelper: this is the main feature, and it is enabled by default. Minecraft's look helper code is swapped for a custom version that stores data to get the angle to a location faster. The author's VisualVM testing showed a 50% to 80% decrease in CPU usage by the AI code. On a server with 25 people constantly online, that meant a gain of 5 to 7 tps.^[1]
• Disable AI Watch Closest Entity: this is off by default. When you turn it on, it removes the AI segment called EntityAIWatchClosest, which is what makes mobs turn their heads toward a nearby entity. You may see a few odd visual issues, but it frees up a lot of CPU usage caused by entities.^[1]
• Disable AI look random: this is also off by default. When you turn it on, entities stop using the look idle AI code. Almost every entity runs it when it has nothing important to do, so removing it can help servers with large populations. The visible effect is that heads sometimes don't rotate, which mostly goes unnoticed.^[1]

If you turn off the EntityLookHelper replacement, you won't see much improvement in the AI code. According to the project page, that is fine as long as you enable the other disable options.^[1]

Where it runs

The mod works when installed on the server only, because it is coded to function without being on the client. It can also be installed on the client only, but that may not do much for your FPS.^[1]

Config in this pack

On the project page, the mod's config file is AI_Improvements.cfg in a folder called bbm inside the config folder. The defaults described above are the mod's own defaults.^[1]

Unverified No config file for this mod was found in the pack, so I can't confirm whether the pack changes any of these values. Check the file in your own instance before assuming the defaults apply.

There isn't much history to cover here, and that's a good sign for a performance mod. All the Mods 10 8.1 ships AI Improvements: Performance Tuning at version 0.5.3, and the mod has been in the pack since All the Mods 10 0.32 or earlier.^[2]

• 0.5.3: updated to Minecraft 1.21. This is the only change listed in the mod's own changelog for that release.^[3]
• All the Mods 10 8.1 includes this 0.5.3 build, using the file AI-Improvements-1.21-0.5.3.jar.^[2]

The pack changelogs have no entries for this mod, so I can't tell you about any pack-specific changes to it across releases.^[2]